Cutting machine

ABSTRACT

It is an object of the present invention to provide a cutting machine capable of keeping an angle of a cutting edge constant. A support block  14  is provided with two arms  14   a   , 14   b  which are spaced at a certain angle, and the arms  14   a   , 14   b  have rotation shafts  12   a   , 13   a  of rotary whetstones  12, 13 , respectively, extending upright from the vicinities of the front ends thereof. The rotary whetstones  12, 13  has, at front ends thereof, flat surfaces  12   b   , 13   b  perpendicular to the rotation shafts  12   a   , 13   a  to grind the one side  11   b  and the other side  11   c  of the cutting edge  11   a  of the cutting blade  11 , respectively. The whetstone holding mechanism  15  can be moved linearly along the guide shaft  16  and can change over grinding states in which the flat surfaces  12   b   , 13   b  of the rotary whetstones  12, 13  into contact with the one side  11   b  or the other side  11   c  of the cutting blade  11 . Even when the grinding progresses, since parallelism between the flat surfaces  12   b   , 13   b  and the one side  11   b  and the other side  11   c  of the cutting blade  11 , so that the angle of the cutting edge is kept constant.

TECHNICAL FIELD

The present invention relates to a cutting machine for cutting a sheetmaterial and the like, and particularly to a cutting machine having thefunction of grinding a cutting blade.

BACKGROUND ART

In general, to a sheet material such as textile fabric, the cutting isperformed to cut it based on a pattern paper or on the datacorresponding to the pattern paper. A cutting machine or the like usedfor the cutting has a grinding function to keep sharpness of a cuttingblade (Cf. Patent Citation 1, for example). The Patent Citation 1discloses a sheet material cutting device for cutting the sheet materialwith a cutting knife which is moved in reciprocation along a verticalaxial line direction and also discloses two different ways of grindingthe cutting knife from both sides of its cutting edge.

FIG. 15 shows those two different concepts on the grinding disclosed byPatent Citation 1. FIG. 15( a) shows one concept on the grinding with arounded surface around outside of periphery of a rotary whetstonedisclosed in its FIG. 11 and the like. FIG. 15( b) shows another concepton grinding with a flat surface of the rotary whetstone perpendicular toan axis thereof disclosed in its FIG. 13 and the like. In the following,the simplified construction is illustrated, for explanatory convenience.Although names and reference numerals of parts may vary, thecorrespondence relation to the two different concepts on the grindingshould be obvious.

In FIG. 15( a), one side 1 b of the cutting edge 1 a of the cuttingknife 1 and the other side 1 c of the same are ground with outsidesurfaces 2 a, 3 a of outer peripheries of two rotary whetstones 2, 3,respectively. The two rotary whetstones 2, 3 are supported at front endsof two arms 4 a, 4 b of a support block 4. The two arms 4 a, 4 b arefixed with spaced apart from each other at a certain angle. The supportblock 4 is capable of oscillating displacement around a pivot shaft 5penetrating intermediate portion between the arms 4 a, 4 b. The pivotshaft 5 supports the cutting knife 1 so as to be capable of moving inreciprocation along a direction vertical to the paper, and is stuck upfrom base 6 which turns in conjunction with a direction of the cuttingedge 1 a of the cutting knife 1. When the support block 4 is madeoscillating displacement with respect to the pivot shaft 5 in onedirection or the other, the one side 1 b of the cutting knife 1 or theother side 1 c of the same can be ground with the related outsidesurface 2 a, 3 a of the rotary whetstone 2, 3. In this regard, however,since the grinding is performed using the cylindrical surface 2 a, 3 a,even when one side 1 b and the other side 1 c of the knife 1 initiallyhave a linear cross-sectional shape, they are varied in cross-section tohave a concave surface, as shown as a shaded area.

In FIG. 15( b), like reference numerals are labeled to correspondingparts to FIG. 15( a), to avoid redundant explanation. The support block4 has mounting surfaces 4 c,4 d on the arms 4 a,4 b at the side facingto the cutting edge 1 a of the cutting knife 1 respectively. The rotarywhetstones 2, 3 have rotate shafts perpendicular to the mountingsurfaces 4 c,4 d and are capable of changing over between grindingstates, in which flat surfaces 2 b,3 b perpendicular to the rotateshafts are put in contact with the one side 1 b of the cutting knife 1or the other side 1 c of the same to grind it. For example, when thesupport block 4 is pivotally displaced in one direction with respect tothe pivot shaft 5, as showing with the dashed line, the flat surface 2 bof the rotary whetstone 2 is switched over to the state of being put incontact with the one side 1 b of the cutting knife 1 to grind it.Likewise, when the support block 4 is pivotally displaced in the otherdirection with respect to the pivot shaft 5, the flat surface 3 b of therotary whetstone 3 is switched over to the state of being put in contactwith the other side 1 c of the cutting knife 1 to grind it. As thecutting knife 1 is ground with the flat surfaces 2 b, 3 b, the linearcross-sectional shape of the cutting knife 1 is kept unchanged, as shownas the shaded area.

Such grinding way of FIG. 15( a), is not only possible by an overalloscillation displacement of the support block 4, but also possible byputting the cylindrical surfaces 2 a, 2 b of the rotary whetstones 2, 3in contact with the one side 1 b of the cutting edge 1 a of the cuttingknife 1 or the other side 1 c of the same, respectively, via a linkmechanism and the like (Cf. Patent Citation 2, for example). Accordingto Patent Citation 2, the rotary whetstones 2, 3 and the whetstonesupporting structure are contained in the turning cylinder which isturned around an R-axis as a rotation shaft of the cutting edge of thecutting blade corresponding to the cutting knife 1. The switching overbetween the grinding states is performed by turning the turning cylinderwhile locking a slide ring mounted on the turning cylinder to bestationary relative to outside. By a relative angular displacementbetween the slide ring and the turning cylinder, each rotary whetstonepivotally displaces individually via the cams and the link mechanism,thereby allowing the switching over between the grinding states.

Patent Citation 1: JP Patent Publication No. Sho 56-8759

Patent Citation 2: JP Patent No. 3390219

DISCLOSURE OF INVENTION Technical Problem

As shown in FIG. 15( a), when the grind is done by using the cylindricalsurfaces 2 a, 3 a of the rotary whetstones 2, 3, the one side 1 b of thecutting edge 1 a and the other side 1 c of the same are varied in crosssectional shape to have a concave surface, as shown as the shaded area.In such cross sectional shape, thin wall at its portion close to thecutting edge 1 a decreases rigidity, while on the other hand, it sharplyincreases in wall thickness at its portion away from such a thin wallportion in the vicinity of the cutting edge 1 a, thereby producing anincreased cutting resistance. After repeating the grind, the change ofthe cross sectional shape becomes large.

As shown in FIG. 15( b), when the cutting knife is ground using the flatsurfaces 2 b, 3 b of the rotary whetstones 2, 3, the linear crosssectional shape of the cutting knife may be kept unchanged, as shown asthe shaded area. But, since the contact of the flat surfaces 2 b, 3 b iscaused by the oscillating displacement about the pivot shaft 5, when thegrinding is repeated, both the one side 1 b and the other side 1 c varyin tilting angle, so that the cutting edge angle decreases and therigidity decreases. If it is assumed that an angular displacement of θ°around the pivot shaft 5 is provided for the dashed line grinding stateof the one side 1 b, then an angular displacement of −θ° around thepivot shaft 5 is required for the grinding state of the other side 1 c.Assuming a cutting edge angle formed between the one side 1 b and theother side 1 c which are converged at the cutting edge 1 a is set ψ°, itfollows that an angle of the space between the flat surfaces 2 b, 3 b is2×θ°+ψ°. This means that the rotary whetstones 2, 3 have to be supportedby the support block 4, with their flat surfaces 2 b, 3 b spaced at anangle of 2×θ°+ψ°, and the support block 4 must be pivoted about thepivot shaft 5 at an angle of at least ±θ°.

It might be impossible to contain such construction for grinding withthe flat surfaces 2 b, 3 b requiring a large space within the turningcylinder as is disclosed in Patent Citation 2. Even if the grinding withthe flat surfaces 2 b, 3 b of the rotary whetstones 2, 3 is tried to beperformed using the mechanism as disclosed in Patent Citation 2, sincethe angle at which the flat surfaces 2 b, 3 b are put in contact withthe one side 1 b and the other side 1 c of the cutting edge 1 a by theoscillating displacement varies with the progress of the grinding, itmight be impossible to keep the angle of the cutting edge.

It is an object of the present invention to provide a cutting machinecapable of grinding in such a manner as to keep an angle of the cuttingedge constant.

Technical Solution

The present invention provides a cutting machine for cutting a sheetmaterial to be cut, which is put on a cutting table, with a cuttingblade provided in a cutting head movable along the cutting table,

wherein the cutting blade is used while both sides of its cutting edgeare ground to keep sharpness of the cutting edge, and

the cutting head is provided with:

a one side use abrasive whetstone having an abrasive surface to contactand to grind one side of the cutting edge of the cutting blade,

an other side use abrasive whetstone having an abrasive surface tocontact and to grind the other side of the cutting edge of the cuttingblade, and

a whetstone holding mechanism that holds abrasive surfaces, with whichthe one side use abrasive whetstone and the other side use abrasivewhetstone grind the cutting blade, leaving a space between the surfacesand being parallel to states, in which the abrasive surfaces of the oneside use abrasive whetstone and the other side use abrasive whetstoneare sharpened respectively,

a guide shaft, penetrated into the whetstone holding mechanism, forguiding it linearly, and

a change over mechanism for moving the whetstone holding mechanism alongthe guide shaft, and for changing over between a standby state and a oneside grinding state or an other side grinding state, in the standbystate the abrasive surfaces of the one side use abrasive whetstone andthe other side use abrasive whetstone being away from both sides of thecutting edge, in the one side grinding state the abrasive surface of theone side use abrasive whetstone being put in contact with the one sideof the cutting edge, in the other side grinding state the abrasivesurface of the other side use abrasive whetstone being put in contactwith the other side of the cutting edge.

In the cutting machine according to the present invention,

wherein said cutting head comprises:

a turning cylinder for containing the cutting blade and being capable ofturning around a rotate shaft of the cutting edge perpendicular to asurface of the cutting table, to change a cutting direction of thecutting blade;

a slide ring provided on the outside of the turning cylinder and capableof following its turning direction; and

a lock mechanism provided at a radial outside of the turning cylinder soas to lock the slide ring to the cutting head;

said change over mechanism and said whetstone holding mechanism arecontained in the turning cylinder to allow the selective switch overbetween the standby state, and the one side grinding state or the otherside grinding state according to a turning angle of the turning cylinderaround the rotate shaft of the cutting edge when the slide ring islocked by the lock mechanism.

In the cutting machine according to the present invention,

wherein said turning cylinder is provided with a rotation ring, whichbeing capable of receiving rotary drive from outside and having innerteeth on the inside of the periphery,

said whetstone holding mechanism is provided with a gear engaging withthe inner teeth of the rotation ring,

the whetstone holding mechanism is capable of oscillating displacementaround the guide shaft so as to keep engagement between the gear and theinner teeth of the rotation ring during said movement along the guideshaft, and

said one side use abrasive whetstone and said other side use abrasivewhetstone rotate by the rotary drive which transmitted to the gearthrough the rotation ring from outside of the turning cylinder and grindsaid cutting blade.

In the cutting machine according to the present invention,

wherein said slide ring having teeth of a uniform pitch on the outsideperiphery,

said lock mechanism including,

-   -   a brake provided with inner teeth separated by shifted phase        into a plurality steps on the periphery, and biased by spring so        as to have different projection amounts at every step, and    -   a drive actuator drives the brake so as to advance and retreat        inward of the turning cylinder, and locks the slide ring by        putting the inner teeth in contact with the teeth of the slide        ring so as to engage when the brake advances.

ADVANTAGEOUS EFFECTS

According to the present invention, the whetstone holding mechanism,provided in the cutting head, holds the abrasive surfaces, to carry outgrinding, of the one side use abrasive whetstone and the flat abrasivesurface of the other side use abrasive whetstone in parallel to the oneside of the cutting blade or the other side of the same, respectively.Since the whetstone holding mechanism, with the movement along the guideshaft caused by the change over mechanism, changes over between thestandby state, in which each abrasive surface is away from both of theone side of the cutting edge, and the one side grinding state, in whichthe one side of the cutting edge is ground, or the other side grindingstate, in which the other side of the cutting edge, the grinding can becarried out in such a manner as to keep an angle of the cutting edgeconstant.

According to the present invention, the structure for grinding thecutting blade and the structure for changing over grinding states arecontained in the turning cylinder capable of turning around the rotateshaft of the cutting edge, and the selective switch over between thegrinding states can be made at a rotation angle of the turning cylinderin the state in which the slide ring is locked by the lock mechanism.

According to the present invention, while the whetstone holdingmechanism moves along the guide shaft in the turning cylinder so as tochange over between the grinding states, the whetstone holding mechanismmakes an oscillating displacement around the guide shaft. In thewhetstone holding mechanism, the gear is provided to receive rotarydrive force from outside via the inner teeth of the rotation ring.Though the whetstone holding mechanism makes linear movement along theguide shaft, by the oscillation movement around the guide shaft, theengaging relation between the gear and the inner teeth of the rotationring is kept. The one side use abrasive whetstone and the other side useabrasive whetstone, which are held by the whetstone holding mechanism,are moved linearly while the state in which the angle between the flatsurfaces for grinding consists with the cutting edge angle is kept, sothat the rotary drive to the abrasive whetstone continues smoothlyduring the change over the side for grinding the cutting edge.

According to the present invention, the lock, mechanism is capable oflocking the slide ring certainly because of engaging between the outerteeth of the slide ring and the inner teeth of the brake. The innerteeth of the brake are provided with in a state separated into aplurality steps and shifted in phase, and are biased by spring so as tohave different projection amount at every step, so that the lockingaccuracy can be improved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a partial sectional bottom view of a cutting machine 10 asan embodiment of the present invention, simplistically showing astructure for grinding a cutting blade 11.

FIG. 2 shows a front sectional view showing a schematic structure of acutting head 20 used in the cutting machine 10 of FIG. 1.

FIG. 3 shows a plan view, a front view and a right side view showing astructure of a whetstone holding mechanism 15 of FIG. 2.

FIG. 4 shows a front sectional view showing a structure of the cuttinghead 20 of FIG. 2 from which the whetstone holding mechanism 15 isomitted.

FIG. 5 shows changing states of the engagement between the gear 34 andthe inner teeth of the inner teeth plate 24 a, while the support block14 is moved linearly along the guide shaft 16 in the cutting head 20 ofFIG. 2.

FIG. 6 shows a plan sectional view of the cutting head 20 of FIG. 2, ina state where the slide ring 22 is not locked by the lock mechanism 23.

FIG. 7 shows a plan sectional view of the cutting head 20 of FIG. 2, ina state where the slide ring 22 is locked by the lock mechanism 23 andthe turning cylinder 21 makes 15 degrees of angular displacement in thecounter-clockwise direction to the slide ring 22.

FIG. 8 shows a sectional bottom view, in which the relationship of FIG.7 between the whetstone holding mechanism 15 and the cutting blade 11 isshown from downward.

FIG. 9 shows a sectional plan view of the structure in which both pitchcircles of the gear 33 and the inner teeth of the inner teeth plate 24 aconsist with each other at the angle 15 degrees of FIG. 8.

FIG. 10 shows a sectional view for the partial structure of the engagingportion between the gear 33 and the inner teeth 24 b at the referenceposition shown in FIG. 5( a).

FIG. 11 shows a plan view and a front view showing the structure of thelock mechanism of FIG. 2.

FIG. 12 shows a plan view and a right side view showing the structure inwhich the lower step teeth 62 are mounted to the output rod 61 a of theair cylinder 61 of FIG. 11.

FIG. 13 shows a plan view showing the structure of the upper step teeth63, the spring 64 and the upper cover 65 of FIG. 11.

FIG. 14 shows a plan view showing a state in which the lock mechanism 23of FIG. 11 locks the slide ring 23.

FIG. 15 shows sectional views showing simplified illustrations of twodifferent known concepts to grind the cutting edge.

EXPLANATION OF REFERENCE

-   -   10 Cutting machine    -   11 Cutting blade    -   11 a Cutting edge    -   11 b One side    -   11 c Other side    -   12, 13 Rotary whetstone    -   12 b, 13 b Flat surface    -   14 Support block    -   15 Whetstone holding mechanism    -   16 Guide shaft    -   17,18 Change over mechanism    -   20 Cutting head    -   21 Turning cylinder    -   21 a Leg    -   22 Slide ring    -   22 a Outer teeth    -   23 Lock mechanism    -   24 Rotation ring    -   25 Knife guide    -   28 Support frame    -   33 Gear    -   35,45,46 Follower    -   36 Cam groove    -   37 Support platform    -   41, 42, 51, 52 Pivot shaft    -   43, 44 Pivoted cam    -   49, 50 Lever    -   53 Projecting portion    -   61 Air cylinder    -   62 Lower step tooth    -   63 Upper step tooth

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a bottom view of a cutting machine 10 as an embodiment ofthe present invention, simplistically showing primary elements forgrinding a cutting blade 11. The cutting blade 11 has a pentagonal crosssectional shape in which a cutting edge 11 a is formed by one tiltedside surface 11 b and the other tilted side surface 11 c being joinedtogether at their tips. The cutting blade 11 is driven to move inreciprocation in a direction perpendicular to paper so as to cut a sheetmaterial to a direction for the cutting edge 11 a to point. A cuttinghead including a mechanism to support and drive the cutting blade 11 ismoved in parallel with and over a cutting table on which the sheetmaterial is supported so that the sheet material can be cut with thecutting edge 11 a shifted in position or changed in direction to point.

The cutting head is provided therein with a whetstone holding mechanism15, placed in front of the cutting edge 11 a of the cutting blade 11,for holding a pair of rotary whetstones 12, 13 via a support block 14.The support block 14 is provided with two arms 14 a, 14 b spaced at acertain angle, and rotation shafts 12 a, 13 a of the rotary whetstones12, 13 extend upwards from the vicinities of front ends of the arms 14a, 14 b, respectively. The rotary whetstones 12, 13 have, at front endsthereof, flat surfaces 12 b, 13 b perpendicular to the rotation shafts12 a, 13 a as grinding surfaces to grind the one side 11 b and the otherside 11 c of the cutting edge 11 a of the cutting blade 11,respectively. The rotary drive for the rotary whetstone 12,13 isperformed, for example, via pulleys 12 c,13 c. The whetstone holdingmechanism 15 can move linearly along a drive shaft, which is shown onlywith a center line in order to simplify. The linear movement makes itpossible to change over between a standby state, in which both of theflat surface 12 b of the rotary whetstone 12 as a one side use abrasivewhetstone and the flat surface 13 b of the rotary whetstone 13 as another side use abrasive whetstone are away from each of the one side 11b of the cutting edge 11 a of the cutting blade 11 and the other side 11c

of the same, and a one side grinding state, in which the flat surface 12b of the rotary whetstone 12 is put in contact with the one side 11 b ofthe cutting edge 11 a, or an other side grinding state, in which theflat surface 13 b of the rotary whetstone 13 is put in contact with theother side 11 c of the cutting edge 11 a. The change over between thegrinding states is performed by change over mechanisms 17, 18. Even whenthe process of grinding progresses, since the parallelism between theflat surface 12 b, 13 b and the one side 11 b or the other side 11 c ofthe cutting blade is kept, the cutting edge angle is kept constant.

FIG. 2 shows a schematic structure of the cutting head 20 used in thecutting machine 10 of FIG. 1. FIG. 2 corresponds to a right side view ofthe construction of the cutting machine 10 shown in FIG. 1. The cuttinghead 20 includes the drive mechanism and the like, placed over thecutting blade 11, for driving the cutting blade 11 in reciprocation,though omitting its illustration. Turning around an R axis as a turningaxis of the cutting edge to change the cutting direction of the cuttingblade 11, is performed by turning of a turning cylinder 21. A slide ring22 is provided under the turning cylinder 21, and turns to follow theturning cylinder by a mechanism will be described later. A lockmechanism 23 is provided at the outside of the slide ring 22 to lockouter teeth 22 a of the slide ring 22 so that the slide ring 22 can belocked to stand still to the cutting head 10. The change over betweenthe grinding states, is performed only by turning the turning cylinder21 while the slide ring is locked by the lock mechanism 23.

There is provided a rotation ring 24 over the slide ring 22 and underthe turning cylinder 21. The turning cylinder 21 has legs 21 a extendingdownwards from the slide ring 22 and supporting a knife guide 25thereon. The knife guide 25 supports the cutting blade 11 so that thecutting blade 11 can be prevented from being deformed or displaced whenmoved vertically. The legs 21 a support a foot presser 26 at lower endsthereof. The foot presser 26 is to be put on the sheet material and thelike to be cut. The whetstone holding mechanism 15 is supported at aposition opposed to the knife guide 25, as described later, by the guideshaft 16 which is supported by the bottom surface of the turningcylinder 21 and is penetrating through the whetstone holding mechanism15. The whetstone holding mechanism 15 is capable not only a lineardisplacement along the guide shaft 16 but also an oscillatingdisplacement around the guide shaft 16. Though the oscillationdisplacement is performed by a guide of a follower 35 which is supportedon the bottom surface of the turning cylinder 21, explanations for amechanism to make a oscillating movement, are to be described later.

The whetstone holding mechanism 15 is provided with a detectingmechanism for cutting edge position 27 which detects a position of thecutting edge 11 a of the cutting blade 11, and detects a wear statecaused by grinding the cutting blade 11. To detect a position of thecutting edge 11 a, the top end of a pin 27 a is contacted with thecutting edge 11 a. The turning cylinder 21 is supported on a supportframe 28 of the cutting head 20 to freely rotate through a shaft bearing29. On upper portion of the turning cylinder 21, a pulley 21 b ismounted to receive a rotary drive force given form outside. The rotationring 24 is supported by the turning cylinder 21 capable of free rotatingthrough the shaft bearing 30. The rotation ring 24 is wound with timingbelt around the outside periphery and receives rotary drive force so asto drive the rotary whetstones 12,13 through the gear 33 which engagesthe inner teeth of the inner teeth plate 24 a. It is described later asfor a lever 49 and a spring 54.

FIG. 3 shows the structure of the whetstone holding mechanism 15 of FIG.2. FIG. 3( a) as a plan view, FIG. 3( b) as a front view and FIG. 3( c)as a right side view, the construction is shown respectively. Eachrotary whetstone 12, 13 is provided with a timing belt 31 wound betweenpulley 12 c, 13 c which is mounted to the rotary shaft 12 a, 13 a and upstep pulley 12 d, 13 d. The timing belt 31 is extended to wind aroundupper and lower pulley 32 a, 32 b. The upper pulley 32 a is mounted at alower end of the drive shaft 34 at the upper end of which the gear 33 ismounted. The lower pulley 32 b rotates freely. Through the support block14, the guide shaft 16 penetrates in horizontal direction which isperpendicular to the vertical drive shaft 34. The support block 14 iscapable of linear move along the guide shaft 16 as well as capable ofoscillating movement around the guide shaft 16. The support block 14 isprovided with a cam groove 36 which fits the follower 35 describedabove, by the linear displacement along the guide shaft 16 as well asthe oscillating displacement, moving trajectory of the gear 33 is ableto be made closer to a circular arc.

FIG. 4 shows a structure of the cutting head 20 of FIG. 2 excluding thewhetstone holding mechanism 15. On the bottom surface of the turningcylinder 21 is mounted the above described follower 35 as well as asupport platform 37 which supports the guide shaft 16. On the bottomsurface of the slide ring 22, are also mounted with change overmechanisms 17, 18 shown in FIG. 1. On the lower part of the rotationring 24, is mounted with the inner teeth plate 24 a, the inner teeth onthe inside periphery of the inner teeth plate 24 a engage with the abovedescribed gear 33.

FIG. 5 shows changing states of engaging between the gear 33 and theinner teeth of the inner teeth plate 24 a, while the support block 14 ismoved linearly along the guide shaft 16. FIG. 5( a) shows misalignmentbetween the pitch circle of the inner teeth and the pitch circle of thegear 33, to the linear displacement along the guide shaft 16. A centralreference position corresponds to the standby position for grinding. Itcould be set that from the reference position, to move by, for example,8 mm in left or right direction, the one side grinding state or theother side grinding state could be reached and the pitch circles of thegear 33 and the inner teeth coincide as shown in FIG. 5( b). Between theinner teeth and the gear 33 the pitch circles coincide so that therotary drive force for the rotary whetstones 12, 13 is able to betransmitted surely. If the gear 33 makes parallel displacement withoutchanging the direction of the rotate shaft 34, at the reference positionas shown in FIG. 5( c), the amount of engaging becomes shallow. Thewhetstone holding mechanism 15 of the present embodiment is capable ofoscillation displacement to the rotate shaft 34 so as to the pitchcircles almost coincide and to make the gear 33 closer to the innerteeth side. In the vicinity of the reference position, even if the pitchcircles do not coincide perfectly, rotation load is not generatedbecause the flat surfaces 12 b, 13 b of the rotary whetstones 12, 13 areaway form both of the one side 11 b and the other side 11 c of thecutting edge 11 a, so that there is no problem.

FIG. 6 shows a sectional bottom view of the structure of the cuttinghead 20 of FIG. 2, in a state the slide ring 22 is not locked by thelock mechanism 23. On the outside of the periphery of the slide ring 22and on the inside of the periphery of the lock mechanism 23 which facingto the slide ring 22, teeth are provided to engage each other. Forexample, in case the slide ring 22 is made with metal material and thelike, it could be possible to integrate the outer teeth 22 a to make onthe out side periphery, it could be also possible to adhere timing beltmade from rubber material like polyurethane rubber to the out side asouter teeth 22 a. The change over mechanisms 17, 18 of FIG. 1 includespivoted cams 43, 44 which are supported at the rear end side to theslide ring 22 by the pivot shafts 41, 42. Compression springs 47, 48 areprovided between the slide ring 22 and the pivoted cams 43, 44respectively and bias the pivoted cams 43, 44 so that the cam surfacesprovided with at side position to contact with the followers 45, 46respectively mounted on the support block 14.

One pair of levers 49, 50 are provided in the hind side of the cuttingblade 11. The levers 49, 50 are supported by pivoted shafts 51, 52,which are arranged to the knife guide 25 side with a narrow space, in astate capable of free oscillating displacement. The front end sides ofthe levers 49, 50 pinch a projection portion 53. A tension spring 54 isprovided between the levers 49, 50 biasing them so as to pinch theprojection portion 53 securely with the front end sides of the levers49, 50. Such an action of the levers 49, 50 makes it possible for theslide ring 22 to follow turning of the turning cylinder 21, and thedisplacement angle of the turning cylinder 21 to the slide ring 22 iskept at the reference angle of 0 degree.

FIG. 7 shows on the contrary to FIG. 6 a state in which the lockmechanism 23 locks the slide ring 22 and the turning cylinder isdisplaced by the angle of 15 degrees to the slide ring 22 in thecounter-clockwise direction. Corresponding to the angle of 15 degrees,the support block 14 performs the linear displacement of the 8 mm shownin FIG. 5( a) along the guide shaft 16. As described above, teeth areprovided with the outside of the periphery of the slide ring 22 and theinside of the periphery of the lock mechanism 23, so that it is possibleto lock surely. As the position of the leg 21 a is however shown similarto that of FIG. 6, for the sake of convenience to explain, the slidering 22 is locked to stand still but is shown in an angular displacementstate. The left side follower 45 of the support block 14 is pushedrightward of the drawing by the pivoted cam 43. The right side follower46 is apart from the pivoted cam 44 so as to receive no action by thepivoted cam 44. The support block 14, capable of moving along the guideshaft 16, moves rightward in the drawing.

FIG. 6 shows the relationship between the whetstone holding mechanism 15and the cutting blade 11 of FIG. 7 as viewed from downward. When thefollower 45 is pushed rightward by the pivoted cam 43, the flat surface12 b of the rotary whetstone 12 is compressed to the one side lib of thecutting edge 11 a so that grind is done. The angle of the turningcylinder 21 is set as a standard angle for grinding. As shown in FIG. 6and FIG. 7, the pivoted cams 43, 44 are pressed inward by thecompression springs 47, 48. While grinding, this compression force isacting.

FIG. 9 shows a plan view of the structure to adapt the pitch circle ofthe gear 33 and that of the inner teeth of the inner teeth plate 24 a tothe angle of 15 degrees as shown in FIG. 8. Into the cam groove 36 setto the support block 14, the follower 35, shown in FIG. 2 and the like,is fitted. As is shown in the drawing, the drive shaft should beperpendicular to the paper surface, the pitch circle of the gear 33should consist with the pitch circle of the inner teeth of the innerteeth plate 24 a, and fitting should be performed properly, the shape ofthe cam groove 36 is so determined. Progress of grinding brings increasein the angle of the turning cylinder 21 in order to act the samecompression force. For example, when the angle reaches to 15 degrees,the cutting blade 11 is stopped to use. However, with such amount ofchange, the compression springs 47, 48 are still able to compresssufficiently, even if the angle remains at 15 degrees, there is no needto change the angle. In this case, the moving distance of the supportblock 14 from the reference position is 8.5 mm. Such displacement likeas 0.5 mm, misalignment of engaging might be negligible, but, by theshape of the cam groove 36 being properly determined, the rotary shaft34 could be made oscillating displacement to be apart from the innerteeth, so that it could be compensated to avoid too deep engaging.

FIG. 10 shows the structure of the engaging portion between the gear 33and the inner teeth 24 b of the inner teeth plate 24 a at the referenceposition shown in FIG. 5( a). If the diameter of the follower 35 and thewidth of the cam groove 36 are set to an identical size, by a settingsof plus tolerance, the follower 35 could tilt the support block 14 inthe cam groove 36, so that tilting of the drive shaft 34 could bring thegear 33 closer to the inner teeth 24 b.

FIG. 11 shows the structure of the lock mechanism 23. FIG. 11( a) is apartial plan view, and FIG. 11( b) is a partial front view. In the lockmechanism 23, on a mounting plate 60, which is mounted to the supportframe of FIG. 2, an air cylinder 61, which becomes a drive actuator, ismounted. On an output rod 61 a of the air cylinder 61, a lower steptooth 62 is mounted. On an upper surface of the lower step tooth 62, aprojecting portion 62 a at one side, a projecting portion 62 b and agroove 62 c at near center are provided. Between the projecting potions62 a, 62 b, a upper step tooth 63 is equipped and is biased to the outerteeth 22 a side by a spring 64 fitted in the groove 62 c. Above theupper step teeth 63, an upper cover 65 is mounted. As shown in FIG. 11(a), with biasing by the spring 64, tooth tops of the upper step tooth 63project to the outer teeth 22 a side. Between the upper step tooth 63and the lower step tooth 62, there exists a misalignment of one halfpitch. The lower step tooth 62 is mounted to the mounting plate 60 by astepped screw 66 and is capable of slid displacement. In the mountingplate 60, a long opening is formed and is penetrated by the steppedscrew 66.

FIG. 12 shows the structure in which the lower step tooth 62 is mountedto the output rod 61 a of the air cylinder 61. FIG. 12( a) is plan view,and FIG. 12( b) is a right side view. Further FIG. 13 shows a plan viewof the structure of the upper step tooth 63, the spring 64 and the uppercover 65.

FIG. 14 shows a state in which the lock mechanism 23 performs to lockthe outer teeth 22 a of the slide ring 22. Illustration of the uppercover 65 is omitted. Tooth tops of the lower tooth 62 and the uppertooth 63 of the lock mechanism act as a brake and engage with the outerteeth 22 a of the slide ring 22 to lock it. FIG. 14( a) is a state inwhich the upper step tooth 63 engages with the outer teeth 22 a, FIG.14( b) is a state in which the lower step tooth 62 engages with theouter teeth 22 a, respectively. When the air cylinder 61 is started topush out the lower step tooth 62, at first, the upper step tooth 63,which is set to project, comes close to the outer teeth 22 a. In case ofboth the upper step tooth 63 and the outer teeth 22 a are capable ofengaging with threads and roots each other, soon the state shown in FIG.14( a) is realized, so that the slide ring 22 is locked. In case offacing threads to threads and roots to roots between the upper steptooth 63 and the outer teeth 22 a, the upper teeth 22 a is pushed andgoes back, as shown in FIG. 14( b), it becomes to a state in which thelower step tooth 62 engages with the outer teeth 22 a.

If the outer tooth is made of rubber material like as polyurethanerubber, because of elasticity, even if the coincidence of the tooth totooth is not perfect, a little amount of misalignment is allowable. Butif the brake is made of a single step teeth, the misalignment may reachone pitch at most until engaging is performed. By shifting of one halfpitch between the upper step tooth 63 and the lower step pitch 62, themisalignment can be decreased to one half pitch at most. If the numberof steps might increase, the misalignment could become smaller. It couldbe possible that no outer teeth 22 a should be provided on the outsideof the periphery of the slide ring 22, but a brake shoe, made of rubberor the like, could be provided on the lock mechanism 23 side.

Although the whetstone holding mechanism 15 is supported below theturning cylinder 21 in the embodiment illustrated above, since thestructure is compact, the whetstone holding mechanism 15 may be properlyarranged according to the structure of the cutting head 20, with lesslimitation on arrangement. Though the whetstone holding mechanism 15 isto be allowed the selective switch over between the grinding states bythe turning of the R-axis, a power source, such as a motor, may beincorporated in the mechanism to move the whetstone holding mechanism byitself. Though the rotary whetstones 12, 13 are used to grind thecutting blade 11, in case that grinding is done during the cutting blade11 is also moved, grinding is possible only by contact of stillwhetstone. Using the rotary whetstones 12, 13, grinding is performedwith high speed, and productivity is avoided from decrease. For drivingrotary whetstones 12, 13, drive source like a motor could be provided inthe turning cylinder 21. Though the cutting blade 11 has a linear shape,to a rotating round cutter cutting, at least one point on the periphery,the concept of the present invention is to be applied to grind both sideof cutting edge as like as the cutting blade 11.

In addition, in the whetstone holding mechanism 15, the rotary whetstone12, 13 are provided at one step to left side and right side, whetstonescould be provided at two steps by attaching rotary whetstones to upperstep pulleys 12 d, 13 d. In this case, the diameter of the whetstonesprovided on upper step, should be smaller than the diameter of therotary whetstones 12, 13.

1. A cutting machine for cutting a sheet material to be cut, which isput on a cutting table, with a cutting blade provided in a cutting headmovable along the cutting table, wherein the cutting head is providedwith: a turning cylinder for containing the cutting blade and beingcapable of turning around a rotate shaft of the cutting edgeperpendicular to a surface of the cutting table, to change a cuttingdirection of the cutting blade; a slide ring provided on the outside ofthe turning cylinder and capable of following its turning direction; alock mechanism provided at a radial outside of the turning cylinder soas to lock the slide ring to the cutting head; a whetstone holdingmechanism which is contained in the turning cylinder and holds abrasivesurfaces, with which the one side use abrasive whetstone and the otherside use abrasive whetstone contact with and grind the one side of thecutting edge and the other side of the cutting edge of the cuttingblade, leaving a space between the surfaces and being parallel tostates, in which the abrasive surfaces of the one side use abrasivewhetstone and the other side use abrasive whetstone are groundrespectively, a guide shaft, penetrated into the whetstone holdingmechanism, for guiding the whetstone holding mechanism linearly, and achange over mechanism, supported by the turning cylinder, for moving thewhetstone holding mechanism along the guide shaft, and for changing overbetween a standby state and a one side grinding state or an other sidegrinding state, in the standby state the abrasive surfaces of the oneside use abrasive whetstone and the other side use abrasive whetstonebeing away from both sides of the cutting edge, in the one side grindingstate the abrasive surface of the one side use abrasive whetstone beingput in contact with the one side of the cutting edge, and in the otherside grinding state the abrasive surface of the other side use abrasivewhetstone being put in contact with the other side of the cutting edge;the turning cylinder is provided with a rotation ring, which beingcapable of receiving rotary drive from outside and having inner teeth onthe inside of the periphery, the whetstone holding mechanism is providedwith a gear engaging with the inner teeth of the rotation ring, anengaging mechanism is further provided with for displacing the whetstoneholding mechanism in oscillation around the guide shaft so as to keepengaging between the gear and the inner teeth of the rotation ring andmake moving trajectory of the gear closer to a circular arc, whilemoving the whetstone holding mechanism along the guide shaft, and theone side use abrasive whetstone and the other side use abrasivewhetstone rotate by the rotary drive which transmitted to the gearthrough the rotation ring from outside of the turning cylinder and grindthe cutting blade.
 2. The cutting machine according to claim 1, whereinsaid engaging mechanism including a follower supported by said turningcylinder and fitted to a cam groove, which is provided in said whetstoneholding mechanism, and the cam groove having a curved shape for thewhetstone holding mechanism to make a oscillating displacement aroundthe guide shaft while the whetstone holding mechanism moves linearlyalong the guide shaft.
 3. The cutting machine according to claim 1,wherein said change over mechanism including one pair of pivoted cams,which are supported at the rear end side to said slide ring, capable ofpinching from both side of a portion of the whetstone holding mechanismthrough which said guide shaft penetrates, and in case said lockmechanism locks the slide ring, by the turning of said turning cylinder,one of the pivoted cam pushes the whetstone holding mechanism along theguide shaft, so that said change over is done between said standby stateand a state in which one of the sides is ground.
 4. The cutting machineaccording to claim 1, wherein said slide ring having teeth of a uniformpitch on the outside periphery, said lock mechanism including, a brakeprovided with inner teeth separated by shifted phase into a pluralitysteps on the periphery, and biased by spring so as to have differentprojection amounts at every step, and a drive actuator drives the brakeso as to advance and retreat inward of the turning cylinder, and locksthe slide ring by putting the inner teeth in contact with the teeth ofthe slide ring so as to engage when the brake advances.
 5. The cuttingmachine according to claim 2, wherein said change over mechanismincluding one pair of pivoted cams, which are supported at the rear endside to said slide ring, capable of pinching from both side of a portionof the whetstone holding mechanism through which said guide shaftpenetrates, and in case said lock mechanism locks the slide ring, by theturning of said turning cylinder, one of the pivoted cam pushes thewhetstone holding mechanism along the guide shaft, so that said changeover is done between said standby state and a state in which one of thesides is ground.
 6. The cutting machine according to claim 2, whereinsaid slide ring having teeth of a uniform pitch on the outsideperiphery, said lock mechanism including, a brake provided with innerteeth separated by shifted phase into a plurality steps on theperiphery, and biased by spring so as to have different projectionamounts at every step, and a drive actuator drives the brake so as toadvance and retreat inward of the turning cylinder, and locks the slidering by putting the inner teeth in contact with the teeth of the slidering so as to engage when the brake advances.
 7. The cutting machineaccording to claim 3, wherein said slide ring having teeth of a uniformpitch on the outside periphery, said lock mechanism including, a brakeprovided with inner teeth separated by shifted phase into a pluralitysteps on the periphery, and biased by spring so as to have differentprojection amounts at every step, and a drive actuator drives the brakeso as to advance and retreat inward of the turning cylinder, and locksthe slide ring by putting the inner teeth in contact with the teeth ofthe slide ring so as to engage when the brake advances.